Armand Marie Leroi announces in his Times op-ed that race
is biologically real (New York Times, March 14, 2005).
The crusty trope that race is a social artifact crumbles in the
face of the bright new genomics, he asserts. Genetic variation
may be greater within groups than between groups, as Richard Lewontin
pointed out back in the dark ages of the 1970s, but only for single
genes. Taken together, across genetic loci allelic distributions
correlate into clusters long recognized as the five races: European,
East Asian, African, Amerindian, and Australasian. So suck it
up, constructionists, race is biologically intrinsic.

Moreover, get out of the way. The recognition that race is inherently
biological, Leroi writes, can improve medical care, "as different
races are prone to different diseases." African Americans, for
example, suffer greater prevalences of heart disease and prostate
cancer. Even if such differences arise from socioeconomic causes,
Leroi argues, we should--ignoring the man behind the curtain--embrace
geneticists' very important mission, "searching for racial differences
in the frequencies of genetic variants that cause diseases."

And yet much of Leroi's article unravels his own argument. Leroi
takes population geneticists to task for caving into political
correctness by investigating "ethnic groups," a euphemism that
conflates human differences across scale. Never mind that population
geneticists prefer the term less out of deference to present sensibilities
than to the data themselves. Work by Luigi Cavalli-Sforza's group
(Cavalli-Sforza 2001, Underhill 2003), among others, show human
history--back to our species' origins--to be marked by layers
of migration sweeping back and forth across the continents, gurgling
here and there into local pools of idiosyncratic admixture. While
the resulting genetic frequencies do not embody a homogenous mush,
neither does a stark black and white favored by the new racialists
result. Instead, genetic maps are marked by fine-scaled and functionally
important population gradients.

Leroi recognizes these complications, but still asks us to ignore
them in favor of, ironically enough, a social construct. Just
as it is difficult to talk of the world's physical topography
in terms of multiple contour lines and elevations and easier to
do so in general terms, such as grouping a variety of tall peaks
as "mountain ranges," "so, too, it is with the genetic topography
of our species." Grouping the billion people of European descent
together as a race is easier, "a shorthand that enables us to
speak sensibly...about genetic rather than cultural or political
differences." So, it would appear that bleaching out complications
when discussing human variation makes life easier. Of course,
as those dastardly social constructionists are apt to ask, easier
for whom?

For one, according to Leroi, the pharmaceutical companies. As
race can affect medical treatment, "many new drugs are now labeled
with warnings that they may not work in some ethnic or racial
groups." That such effects need not be predominantly biological
in origin apparently matters little. Leroi admits differences
among races arise from population averages alone. But as we are
unlikely to have individuals' genomes sequenced any time soon,
and presumably won't be able to individualize medical treatment
that way, we'll just have to accept a racialized medical genetics.
Nothing like an argument of expediency to convince a crowd. The
pharmaceutical companies are doing it, so get with it, baby!

Here, Leroi, an evolutionary developmental biologist, bumbles
back into the typology the Darwinian revolution revoked. As Ernst
Mayr (1976, 2004) explained, until the early 19th century biologists
classified species in essentialist terms. A specific type or specimen
defined a species and any variation from the type was considered
deviant or unreal. In statistical terms, a centroid measure such
as the mean phenotype defined the species, while the variance
was thought noise. Typological definitions accounted for the differences
among species and, without variation, explained the impossibility
of evolution.

Darwin and his colleagues turned biology on its head. The population
thinking they introduced emphasized the variation in populations.
As natural history studies accumulated, it became apparent individual
organisms varied in just about any and all characteristics, both
across and within species. Individuals even changed over the course
of their lifespans. Here, averages became thought of as constructs
and the variances the reality. Variation's reality proved fundamental
to Darwin's natural selection. The greater the variation in the
population, the faster natural selection works and adaptations
arise.

Mayr declared the distinction between the two kinds of thinking
about populations couldn't be overemphasized. He noted its social
consequences. Essentialisms form the core of all racialist theories
of human populations, in which all members of a race are thought
exhibiting characteristics of the race type. Even as population
biologists use differences in averages to heuristically distinguish
populations--human or otherwise--by race or subspecies, individuals
clearly vary in all traits and can be reaggregated from trait
to trait.

Are we to assume that African Americans and other minority groups
carry the most susceptible alleles for every one of these diseases?
Can we pretend that the vagaries of mutational chance just happened
to deal African Americans the greatest susceptibilities for every
ailment on our awful list? While there are indeed well-documented
examples of illness with important genetic roots, for a framework
addressing health disparities we'd exert greater impact by placing
our attention back on the man behind the curtain. Racism and other
sources of population-level stress have, by way of their emotional
and material deprivations, definitional effect on individuals
as early as conception, as well as on the populations of which
they are a part. Racism shapes ontogeny, regardless of allelic
frequencies. And it's to that relationship and its overdetermination
of the correlation of diseases where research and social action
need to be directed.

For most geneticists, then, there appear two unpleasant paths.
One involves accepting population disparities in health outcomes
are largely driven by social constructs such as racism, rendering
genetics' role ancillary. A second path, the one Leroi has taken,
means pushing back and declaring race genetic. Given the country's
political economy this second one may indeed be the road many
will choose, a choice for which it is fast becoming apparent they
will be greatly rewarded.

There may be a third path. Biologists and social scientists can
work together under the umbrella of history. Health outcomes emerge
out of layers of historical processes--some ancient, others more
immediate. While it may jump to mind that evolutionary processes
are the ancient ones, evolution generates novelty daily, as HIV
quasispecies show. Human social processes, on the other hand,
have been operating in one form or another since the origin of
the species, even as they have undergone fundamental changes across
history. So there are likely interactions occurring across scales
of biocultural organization worth study by researchers of a variety
of disciplines.

In that context social scientists can comfortably assimilate
the idea that genes exist and may have effect on an individual's
pathologies. Biologists, in turn, should come to terms with public
health data that clearly indicate the means by which to incur
the greatest impact on population health involve altering social
circumstances, with dividends for all. End racist practices, end
economic exploitation, and everybody's health improves. For the
benefit of those who don't believe it we should run the experiment
for a few generations and see what results.

Robert Wallace is a research associate in the Department of
Biology at the City College of New York. Dr. Wallace's current
work focuses on the evolutionary ecology of HIV and Kaposi's sarcoma-associated
herpesvirus.